Casa Chameleon Las Catalinas An adults-only boutique resort with 21 exquisitely designed private villas. Each infinity pool has an incomparable and highly Instagrammable view. casa chameleonhotels.com; doubles from US$495. Nayara Springs Bask in your own mineral-water plunge pool while looking up at the majestic Arenal Volcano at this romantic property. You can also enjoy the tropical flora and fauna—including sloths— and feast on local culinary delights at Amor Loco, the hotel's fine-dining spot. Arenal Volcano National Park; nayarasprings.com; villas from US$850.